Nowadays, cloud-based storage services are rapidly growing and becoming an emerging trend in data storage field. There are many problems when designing an efficient storage engine for cloud-based systems with some requirements such as big-file processing, lightweight meta-data, low latency, parallel I/O, deduplication, distributed, high scalability. Key-value stores
played an important role and showed many advantages when solving those problems. This paper presents Sequential Chunk Identity with lightweight metadata to build Big File Cloud (BFC). It proposes algorithms and architecture to handle many problems in a big-file cloud storage system based on key-value store. This research applied the advantages of ZDB - an in-house key-value store which was optimized with auto-increment integer keys for solving big-file storage problems efficiently. The results can be used for building scalable distributed data cloud storage that support big-file with size up to several terabytes.